The present invention relates generally to fastener-driving tools used to drive fasteners into workpieces, such tools typically being powered by combustion, pneumatics, electricity, powder activated or by other sources.
Fastener-driving tools typically include a housing enclosing a power source which drives the fasteners, a handle or grip and a magazine to hold and advance fasteners for driving into the workpiece by the power source. Fasteners for such tools are typically provided in linear strips in which adjacent fasteners are held together with adhesive, welded wire, plastic or paper webbing, collation strips or the like. In the magazine, a follower biased by a return spring urges the fasteners from a rear end of the magazine, typically where the fasteners are loaded into the magazine, to the front end of the magazine which is adjacent a nosepiece/shear block. In the nosepiece/shear block, the fasteners are impacted by a reciprocating drive blade and driven into the workpiece.
Conventional tools typically are provided with magazines capable of holding either single or double fastener strips. Pneumatic framing tools are manufactured almost exclusively with two strip capacity magazines, since these tools are used in production applications where large volumes of fasteners are driven. The larger capacity magazine reduces the reloading interruption period by 50%.
In contrast, cordless portable fastener driving tools, especially of the framing type, are typically provided only with single fastener strip capacity magazines. The lower capacity of the magazine is designed to improve portability, tool balance and user ergonomics. In addition, cordless tools are intended to be usable in tight or confined areas such as roof trusses and remodeling projects, where longer, higher capacity magazines are a hindrance.
Despite the above-identified conventions, there is a need for users of portable tools to have the ability to load multiple fastener strips at a time for some applications. One proposed solution is to provide multiple magazines, one with a single fastener strip capacity, the other with multiple fastener strip capacity. However, disadvantages of this arrangement include the duplication of magazine components such as return springs, associated brackets, and nosepiece/shear block components, depending on the type of tool being considered, as well as the resulting additional weight, bulk and cost. Another disadvantage of multiple magazines is the problem of jobsite storage of the spare magazine.
Thus, there is a need for a fastener-driving tool having the capability of employing either one or multiple fastener strips, and in a way that addresses the problems discussed above.